addkineticlaw

Create kinetic law object and add to reaction object

Syntax

kineticlawObj = addkineticlaw(reactionObj, 'KineticLawNameValue')
kineticlawObj= addkineticlaw(..., 'PropertyName', PropertyValue, ...)


Arguments

reactionObj

Reaction object. Enter a variable name for a reaction object.

KineticLawNameValue

Property to select the type of kinetic law object to create. For built-in kinetic law, valid values are: 'Unknown', 'MassAction', 'Henri-Michaelis-Menten', 'Henri-Michaelis-Menten-Reversible', 'Hill-Kinetics', 'Iso-Uni-Uni', 'Ordered-Bi-Bi', 'Ping-Pong-Bi-Bi', 'Competitive-Inhibition', 'NonCompetitive-Inhibition', and 'UnCompetitive-Inhibition'. Find valid KineticLawNameValue by using sbioroot to create a SimBiology® root object, then query the object with the commands rootObj.BuiltinLibrary.KineticLaws and rootObj.UserDefinedLibrary.KineticLaws. sbiowhos -kineticlaw lists kinetic laws in the SimBiology root, which includes kinetic laws from both the BuiltInLibrary and the UserDefinedLibrary.

Description

kineticlawObj = addkineticlaw(reactionObj, 'KineticLawNameValue') creates and adds a KineticLaw object to the reactionObj.

In the kinetic law object, this method assigns a name (KineticLawNameValue) to the property KineticLawName and assigns the reaction object to the property Parent. In the reaction object, this method assigns the kinetic law object to the property KineticLaw.

modelObj = sbiomodel('cell');
reactionObj = addreaction(modelObj, 'a -> b');
kineticlawObj = addkineticlaw(reactionObj, 'MassAction');
parameterObj = addparameter(kineticlawObj, 'K1_forward', 0.1);
set(kineticlawObj, ParameterVariableName, 'K1_forward');

KineticLawNameValue is any valid kinetic law definition. See Kinetic Law Definition for a definition of kinetic laws and more information about how they are used to get the reaction rate expression.

kineticlawObj= addkineticlaw(..., 'PropertyName', PropertyValue, ...) constructs a kinetic law object, kineticlawObj, and configures kineticlawObj with property value pairs. The property name/property value pairs can be in any format supported by the function set. The kineticlawObj properties are listed in Property Summary.

Note

To define a Hill kinetic rate equation with a non-integer exponent that is compatible with DimensionalAnalysis, see Define a Custom Hill Kinetic Law that Works with Dimensional Analysis.

Property Summary

Properties for kinetic law objects

Type	Display SimBiology object type
UserData	Specify data to associate with object

Examples

Convert Substrate into Product Using Henri-Michaelis-Menten Kinetics

This example shows how to simulate the conversion of a substrate into a product using the Henri-Michaelis-Menten enzyme kinetics.

Create a model named mymodel.

model = sbiomodel('mymodel');

Add a reaction that represents the conversion of a substrate to a product.

reaction = addreaction(model,'Substrate -> Product');

Add the built-in Henri-Michaelis-Menten kinetic law to the reaction.

kineticLaw = addkineticlaw(reaction,'Henri-Michaelis-Menten');
kineticLaw.Expression

ans = 
'Vm*S/(Km + S)'

The kinetic law has two parameters and a species that you need to define. View these parameters.

kineticLaw.ParameterVariables

ans = 2×1 cell
    {'Vm'}
    {'Km'}

kineticLaw.SpeciesVariables

ans = 1×1 cell array
    {'S'}

To define the parameters, create two parameter objects and set parameter values.

Vm_param = addparameter(kineticLaw,'Vm_param','Value',6.0);
Km_param = addparameter(kineticLaw,'Km_param','Value',1.25);

Map the parameters accordingly by setting the ParameterVariableNames property. This associates the parameters in the expression with the two parameters you just created using a one-to-one mapping in the order given.

kineticLaw.ParameterVariableNames = {'Vm_param','Km_param'};

Also associate the Substrate species with the species S in the expression.

kineticLaw.SpeciesVariableNames = {'Substrate'};

Verify the mapping by looking at the reaction rate and checking the parameters and species are correctly substituted according to the expression.

reaction.ReactionRate

ans = 
'Vm_param*Substrate/(Km_param+Substrate)'

Enter the initial amount of the substrate species for simulation.

model.Species(1).InitialAmount  = 8;

Simulate the model and plot results.

simdata  = sbiosimulate(model);
sbioplot(simdata);